Telegraph transmitter



Aug. 30, 1927. 1,540,541

w. G. FLUHARTY TELEGRAPH TRANSMI TTER I 2 Sheets-Sheet l TRANSMITTINGRELAY SOUN DE R 1 40 Invader.

Wiz ziam (iEluizm-Z Patented Aug. 30, 1927.

UNITED STATES PATENT. OFFICE.

WILLIAM G.- FLUHARTY, OF

.ROCKVILLE CENTER, NEW YORK, ASSIGNOR TO THE WESTERN UNION TELEGRAPHCOMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEGRAPH TRANSMITTER.

Application fi1ed August 1, 1924. Serial No. 729,599.

The present invention relates to semi-automatic transmitters.

More particularly the invention relates to semi-automatic transmittersfor telegraph codes comprising dot, dash, and space units, such forexample as the Morse, continental, and like codes. In priorsemi-automatic senders, such as the well known and commonly usedvibroplex type, utilizing vibrating reeds to transmit the dots, thelength or time interval of dots, dashes, and spaces depend largely uponthe operator. The variations in energy applied to the vibratory membermay result in shortened or so-called pin dots, which are lost on longlines where appreciable attenuation cur, while the key may be held overon the dash side for such short interval that only a dot is transmitted.A further source of error arises due to too rapid changing from dot todash, or too rapid movement of the key to the dash contact to permit aproper space between successive dashes, which results in crowding of thesignals. Due to these variations in the signals produced on the priortransmitters, the receiving operator experiences difficulty in catchingsignals, which results in error and loss of time.

An object of the invention is to provide a simplified and moreeffiecient semi-automatic transmitter in which the dots are uniform inlength, and the Clashes and spaces are mechanically limited to minimumtime intervals so that crowding and clipping of signals becomesimpossible and less skilled operators may be employed.

A further object of the invention is the provision of positivemechanically driven transmitting which will transmit in uniform mannerindependently of wide variations in the manual operation.

Still another object of the invention is the provision of a novel commondrive arrangement for a plurality of transmitters in which each operatorcan independently control the operating speed of his own machine atwill.

Further objects of pear in the following preferred embodiments of which-I Fig. 1 is a perspective showing a single assembled transmitter.

Fig. 2 is a more or less diagrammatic view the invention will apdetaileddescription of the invention of and distortion ocshowing the essentialparts oft-he transmitting apparatus and circuit arrangement.

Fig. 3 is a sectional plan view showing the essential parts of theapparatus.

Fig. 4 is a sectional view taken along line 4-4 of Fig. 3.

Fig. 5 is a fragmental sectional view taken along line 5-5 of Fig. 3.

' Fig. 6 is a fragmental sectional view taken along line 6-6 of Fig. 3.i

v Fig. 7 is a more or less diagrammatic view showing an arrangement fordriving a plurality of transmitters from a common drive shaft.

Referring to the drawings. a. motor 10 of any well known form, throughgears 11 and 12, drives a suitably journalled shaft 13. Secured to androtatable with the end of shaft 13 is a drive member 14 in which aresecured flat spring members 15 held in position by a locking spring ringmember 16. Springs 15 frictionally grip a. driven'member 17 of leather,wood, fiber, or any suitable material. Driven'member 17 is secured toand rotatable with a shaft 18 supported and journalled in plates 19which are held in spaced relation by members 20 and secured to a baseplate 21. Mounted on shaft- 18 is a cam 22, provided with a plurality ofactuating projections 23. An insulating block 24 secured to a. spring 25engages the periphery of 22 in. such manner that as shaft 18 rotates,projections 23 force contact 26 carried by spring 25 into engagement CJIwith a contact 27 carried by a spring 28.

Springs 25 and 28 are mounted on a support 29 and are insulated fromeach other and the base by'insulating blocks 30. Secured to the outerend of shaft 18 are stop wheels 31 and 32 each provided with the samenumb-er of teeth as there are projections 23 on cam 22. Coacting withthe teeth on wheel 31 is a stop member 33 pivotally supported from 19 ona stud 34, and provided with a stop projection 35 adapted to engage theteeth of wheel 31 and arrest rotation of the shaft 18. A stop member 36pivotally mounted on stud 37 is provided with a stop projection 38adapted to engage'theteeth of wheel 32 to arrest the rotation of shaft18. Member 33 is normally held by a spring 39 against an adjustable stopscrew 40 supported on extension 41 of a key 42 which is pivotallysecured to base 21 by a stud 43. An adjustable stop screw 44 suitablysupported from member 19 limits the motion of member 33 to the left inFigs. 1, 2 and 4. Member 36 at its upper end is pressed into engagementwith adjustable spacing pin 45 secured in an extension of member 33,through the action of a compression spring 46. Spring 46 is seat ed atone end over a projection of member 36 and at the other end is supportedon a seat 47 which is adjustably supported on a screw 48 from aprojection 49 of plate 19. The movement of the parts to the right inFigs. 1, 2 and 4 is limited by an adjustable stop pin 50. Formedintegrally with menn ber 36 is an extension 51 which is adapted to beengaged by a pin 52 secured in arm 53 of key 42.

The parts are so proportioned and arranged that with key 42 unactuated,the

positions as shown in Fig. 4 will be assumed. In this position of parts,pro ection 38 of member 36 engages a tooth of wheel 32 and shaft 18 isheld from rotation, and

cam projections 23 are so positioned with respect to block 24 thatcontacts 26 and 27 will be open. Motor and shaft 13 will be incontinuous rotation but the member 17 will simply slip between springs15. If key 42 is shifted to the right in Figs. 1 and 2, pin 52 will moveto the left in Fig. 4, shifting extension 51 of member 36 to the left,and stop projection 38 to the right in Fig. 4 out of engagement withwheel 32. This frees shaft 18 for rotation under the influence of thefriction drive. As long as the key is held to the right, stop 38 will beheld out of the path of the teeth on wheel 32, member 33 will be heldagainst stop 44 by the tension of spring 39, and cam projections 23 willclose and permit opening of contacts 26 and 27 for successive uniformand regularly spaced intervals. The operation of contacts 26 and 27 inwell known manner, may control a line circuit and a local sounder. Whenthe operator has heard the desired number of dots on his local sounder,the key may be released, and the parts will restore to the positionshown in Fig. 4 under the influence of springs 39 and 46. Stop 38 willnow assume a posit-ion in the path of rotating wheel 32 and shaft 18will be brought to rest with contacts 26 and 27 open as shown in Fig. 5.

When a dash is to be transmitted, key 42 is moved to the left, causingpin to force member 33 to the right in Fig. 4. Pin will simultaneouslyforce member 36 to the right withdrawing stop 38 from the engage- G0ment with the tooth of wheel 32, and as shaft 18 is released, stop 35will move into the path of the first tooth on wheel 31. Shaft 18 willnow rotate until the first tooth of wheel 31 engages stop 35 when shaft18 will again be brought to rest. The

relative position of the teeth on wheel 31 with respect to camprojections 23 is such that with shaft 18 arrested by stop 35, contacts26 and 27 will be helo closed. As long as key 42 is held to the left,the contacts will remain closed and an impulse will be transmitted. Assoon as "the key is released the parts will restore to unactuatedposition shown in Fig. 4, and shaft 18 will be arrested by stop 38; Iftwo consecutive dashes are to be transmitted the key must be restored tounactuated position before stop 35 will release shaft 18 to permitinterruption of the contacts. It will be noted that the arrangement issuch as to require practically the full movement of key 42 to the rightor left before shaft 18 is freed, and that a very slight restoringmovement will position steps 35 and 38 in arresting position so that assoon as rotation is initiated the key may be released, and a full dotwill be transmitted, while on the dash side an impulse at least as longas a dot will also be transmitted. It is also clearly impossible to clipspaces as the minimum spaces between each .impulse will be determined bythe angular spaces between projections 23 and the speed of rotation ofshaft 18. i

The transmitter shown in Fig. 1 has an individual motor. In officeswhere a large number of operators are located a common motor may beprovided from which all of the transmitters are driven. An improvedcommon drive arrangement is shown in Fig. 7. The motor may be of anywell known type, and may have its speed controlled by a rheostat 61inwell known manner. Motor 60 drives a shaft 62 supported in suitablejournals 63 and has mounted thereon transmitter drive gears 64. Gears 64mesh with and drive gears 65 which in turn are mounted upon and driveshafts 66. Shafts 66 are supported in journals 67 and have secured tothe ends thereof friction plates 68. Plates 68 contact with and drivemembers 69 which are provided with extensions 70 at one end, and at theother end are rotatably supported on the end of and longitudinallymovable with screw threaded support members 71. Extensions 70 areslidably journalled in bearings 72 and members 71 are supported in screwthreaded members 73. The arrangement of parts is such that members 69may be adjusted to any desired position along the faces of the coactingfriction drive plates 69'by adjusting screws 71, and will remain in theset position until mem bers 71 are readjusted. Members 69 engage anddrive friction plates '74 which are in turn secured to and drivesuitably supported shafts. Shafts 7 5 are connected to and drive shafts13 of the transmitter, as above described, by suitable flexible andreadily cletachable drive connections 76.

In operation each operator can connect his own transmitter to thecircuit he is operating and to one of the shafts 75. By rotating screw71 he can position member 69 to drive his transmitter at the speed mostsuited to his own requirements and transmit without relation to thespeeds of other transmitters being driven from the same motor 60.

Having described preferred embodiments of the invention, what is desiredto be secured by Letters Patent and claimed as new 1. A transmittercomprising a single set of transmitting contacts operative to transmiteither dots or dashes, a shaft carrying an actuating cam for saidtransmitting contacts, a continuously operating motor having aconstantly engaged friction clutch operatively connected to saidshaft,and means for controlling the operation of said shaft including apair of stop members adapted to arrest said cam in differing relativepositions with respect to said transmitting contacts to thereby causethe transmission of uniformly spaced impulses of uniform length or toarrest said cam in a position to transmit prolonged impulses of variablelength and a single manually actuated lever controlling the operation ofboth stop members.

2. A; telegraph transmitting system comprising a plurality ofsemi-automatic transmitters of the type set forth herein, a common driveshaft for said transmitters and a variable speed control interposedbetween each of said transmitters and said drive shaft to thereby permitcontrol of the speed of each transmitter independently of the speeds ofthe remaining transmitters.

3. A transmitter comprising a single set of transmitting contacts,operative to transgagement and the other normally disen gaged therefrom,and a single manually actuated lever controlling both stop members topermit said shaft to rotate for any desired period or to arrest theshaft at will with the cam in dilfering relative positions with respecttosaid transmitting contacts, thereby causing either the transmission ofuniformly spaced dot impulses of uniform length or the transmission ofprolonged dash impulses of the desired lengths.

4. In a transmitter as set forth in claim 3, the actuating cam beingprovided with a plurality of symmetrically arranged cam elements, andeach toothed member having teeth corresponding to said cam elements, theteeth on the tWo members being in staggered arrangement.

In testimony whereof I affix my signature.

WVILLIAM G. FLUHARTY.

